History books are located within the following letter ranges:
D: History: General and Old World
E-F: History: New World
G-GN: Geography, Anthropology
HM-HX: Social Sciences (Sociology, Social History, Ideologies)
This is true regardless of location so books in Special Collections (1st floor), Reference (3rd floor) and Main Stacks (4th-5th floors) with these starting letters on the spine will relate to political science.
Use of WorldCat or HORNETCat will guide to books held by the Levi Watkins Learning Center. WorldCat will also guide you to books held by other libraries.